Rogue - Really good for P2. Strong asset to bring.
Warlock - All of them should be affliction. All of them should have Kil'jaden cunning. They are the single strongest class in the fight, by a lot.
Mage - Arcane Arcane Arcane. Anyone who says go frost or fire is wrong and dumb. Go Arcane and AoE from melee range. Mages are also awesome on this fight.
Hunter - Very strong, but must be Survival. BM is pointless. Best class to be the "anchor" for ball tossing because they can deterrence the burrow on a 1m CD and have good AoE coverage from range.
Warrior - Warriors should stay on the boss sub 20%. After a certain point the entire raid will be AoEing the adds first (we say 6 adds, wave 1), and doing "what they can" to Sha after adds are weak or inbetween via multi-dotting. The necessary decay of Sha of Fear's HP between burrows depreciates from 4% before this to 3%. Warriors however, can do both sub 20%. Their Execute almost backpacks the raid's DPS on Sha as everyone else is AoEing. Their AoE the rest of the fight is fantastic. And if something stupid happens and the wrong tank gets naked, they can get naked too in a pinch and not die. Also they are pretty great in Phase 1 if you do the platform lockout strat.